This invention relates generally to refrigerators and more particularly to an improved temperature control system and air flow distribution arrangement for a multi-compartment refrigerator, including independent freezer compartment and fresh food compartment temperature controls.
Generally, in a dual compartment refrigerator of the forced air circulation type, a single fan and a single evaporator are provided usually in the freezer compartment. In this type refrigerator, as disclosed in U.S. Pat. Nos. 3,126,717-Schumacher and 3,320,761-Gelbard, assigned to General Electric Company, assignee of the present invention, thermostatic control of the evaporator is achieved, using an air temperature sensing element located in the warmer fresh food storage compartment. To provide desired temperature differential between the fresh food storage compartments, an adjustable air flow divider is employed to proportion the flow of air cooled by the evaporator through the frozen and food storage compartments.
The temperature in the fresh food compartment is thermostatically controlled by energizing the compressor and fan in response to the cooling requirements of the fresh food compartment. Being under actual thermostatic control, the temperature is maintained quite efficiently at approximately the desired temperature. The temperature in the freezer compartment is not thermostatically controlled but rather is controlled by varying the flow of refrigerated air from the evaporator to the fresh food compartment, thereby forcing the compressor to run for either longer or shorter periods of time to satisfy the requirements of the fresh food compartment, indirectly affecting the temperature in the freezer compartment.
The present invention overcomes the problem of temperature control by providing independent temperature sensing controls in each of the compartments wherein the freezer temperature control energizes the compressor and fan, while the fresh food control energizes the fan only and causes air flow into the fresh food compartment from the freezer compartment.